1 //===--- TokenAnnotator.cpp - Format C++ code -----------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief This file implements a token annotator, i.e. creates
12 /// \c AnnotatedTokens out of \c FormatTokens with required extra information.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "TokenAnnotator.h"
17 #include "clang/Basic/SourceManager.h"
18 #include "llvm/Support/Debug.h"
19 
20 #define DEBUG_TYPE "format-token-annotator"
21 
22 namespace clang {
23 namespace format {
24 
25 namespace {
26 
27 /// \brief A parser that gathers additional information about tokens.
28 ///
29 /// The \c TokenAnnotator tries to match parenthesis and square brakets and
30 /// store a parenthesis levels. It also tries to resolve matching "<" and ">"
31 /// into template parameter lists.
32 class AnnotatingParser {
33 public:
34   AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
35                    IdentifierInfo &Ident_in)
36       : Style(Style), Line(Line), CurrentToken(Line.First),
37         KeywordVirtualFound(false), AutoFound(false), Ident_in(Ident_in) {
38     Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
39     resetTokenMetadata(CurrentToken);
40   }
41 
42 private:
43   bool parseAngle() {
44     if (!CurrentToken)
45       return false;
46     ScopedContextCreator ContextCreator(*this, tok::less, 10);
47     FormatToken *Left = CurrentToken->Previous;
48     Contexts.back().IsExpression = false;
49     // If there's a template keyword before the opening angle bracket, this is a
50     // template parameter, not an argument.
51     Contexts.back().InTemplateArgument =
52         Left->Previous && Left->Previous->Tok.isNot(tok::kw_template);
53 
54     while (CurrentToken) {
55       if (CurrentToken->is(tok::greater)) {
56         Left->MatchingParen = CurrentToken;
57         CurrentToken->MatchingParen = Left;
58         CurrentToken->Type = TT_TemplateCloser;
59         next();
60         return true;
61       }
62       if (CurrentToken->isOneOf(tok::r_paren, tok::r_square, tok::r_brace,
63                                 tok::question, tok::colon))
64         return false;
65       // If a && or || is found and interpreted as a binary operator, this set
66       // of angles is likely part of something like "a < b && c > d". If the
67       // angles are inside an expression, the ||/&& might also be a binary
68       // operator that was misinterpreted because we are parsing template
69       // parameters.
70       // FIXME: This is getting out of hand, write a decent parser.
71       if (CurrentToken->Previous->isOneOf(tok::pipepipe, tok::ampamp) &&
72           CurrentToken->Previous->Type == TT_BinaryOperator &&
73           Contexts[Contexts.size() - 2].IsExpression &&
74           Line.First->isNot(tok::kw_template))
75         return false;
76       updateParameterCount(Left, CurrentToken);
77       if (!consumeToken())
78         return false;
79     }
80     return false;
81   }
82 
83   bool parseParens(bool LookForDecls = false) {
84     if (!CurrentToken)
85       return false;
86     ScopedContextCreator ContextCreator(*this, tok::l_paren, 1);
87 
88     // FIXME: This is a bit of a hack. Do better.
89     Contexts.back().ColonIsForRangeExpr =
90         Contexts.size() == 2 && Contexts[0].ColonIsForRangeExpr;
91 
92     bool StartsObjCMethodExpr = false;
93     FormatToken *Left = CurrentToken->Previous;
94     if (CurrentToken->is(tok::caret)) {
95       // (^ can start a block type.
96       Left->Type = TT_ObjCBlockLParen;
97     } else if (FormatToken *MaybeSel = Left->Previous) {
98       // @selector( starts a selector.
99       if (MaybeSel->isObjCAtKeyword(tok::objc_selector) && MaybeSel->Previous &&
100           MaybeSel->Previous->is(tok::at)) {
101         StartsObjCMethodExpr = true;
102       }
103     }
104 
105     if (Left->Previous &&
106         (Left->Previous->isOneOf(tok::kw_static_assert, tok::kw_if,
107                                  tok::kw_while, tok::l_paren, tok::comma) ||
108          Left->Previous->Type == TT_BinaryOperator)) {
109       // static_assert, if and while usually contain expressions.
110       Contexts.back().IsExpression = true;
111     } else if (Line.InPPDirective &&
112                (!Left->Previous ||
113                 (Left->Previous->isNot(tok::identifier) &&
114                  Left->Previous->Type != TT_OverloadedOperator))) {
115       Contexts.back().IsExpression = true;
116     } else if (Left->Previous && Left->Previous->is(tok::r_square) &&
117                Left->Previous->MatchingParen &&
118                Left->Previous->MatchingParen->Type == TT_LambdaLSquare) {
119       // This is a parameter list of a lambda expression.
120       Contexts.back().IsExpression = false;
121     } else if (Contexts[Contexts.size() - 2].CaretFound) {
122       // This is the parameter list of an ObjC block.
123       Contexts.back().IsExpression = false;
124     } else if (Left->Previous && Left->Previous->is(tok::kw___attribute)) {
125       Left->Type = TT_AttributeParen;
126     } else if (Left->Previous && Left->Previous->IsForEachMacro) {
127       // The first argument to a foreach macro is a declaration.
128       Contexts.back().IsForEachMacro = true;
129       Contexts.back().IsExpression = false;
130     }
131 
132     if (StartsObjCMethodExpr) {
133       Contexts.back().ColonIsObjCMethodExpr = true;
134       Left->Type = TT_ObjCMethodExpr;
135     }
136 
137     bool MightBeFunctionType = CurrentToken->is(tok::star);
138     bool HasMultipleLines = false;
139     bool HasMultipleParametersOnALine = false;
140     while (CurrentToken) {
141       // LookForDecls is set when "if (" has been seen. Check for
142       // 'identifier' '*' 'identifier' followed by not '=' -- this
143       // '*' has to be a binary operator but determineStarAmpUsage() will
144       // categorize it as an unary operator, so set the right type here.
145       if (LookForDecls && CurrentToken->Next) {
146         FormatToken *Prev = CurrentToken->getPreviousNonComment();
147         if (Prev) {
148           FormatToken *PrevPrev = Prev->getPreviousNonComment();
149           FormatToken *Next = CurrentToken->Next;
150           if (PrevPrev && PrevPrev->is(tok::identifier) &&
151               Prev->isOneOf(tok::star, tok::amp, tok::ampamp) &&
152               CurrentToken->is(tok::identifier) && Next->isNot(tok::equal)) {
153             Prev->Type = TT_BinaryOperator;
154             LookForDecls = false;
155           }
156         }
157       }
158 
159       if (CurrentToken->Previous->Type == TT_PointerOrReference &&
160           CurrentToken->Previous->Previous->isOneOf(tok::l_paren,
161                                                     tok::coloncolon))
162         MightBeFunctionType = true;
163       if (CurrentToken->Previous->Type == TT_BinaryOperator)
164         Contexts.back().IsExpression = true;
165       if (CurrentToken->is(tok::r_paren)) {
166         if (MightBeFunctionType && CurrentToken->Next &&
167             (CurrentToken->Next->is(tok::l_paren) ||
168              (CurrentToken->Next->is(tok::l_square) &&
169               !Contexts.back().IsExpression)))
170           Left->Type = TT_FunctionTypeLParen;
171         Left->MatchingParen = CurrentToken;
172         CurrentToken->MatchingParen = Left;
173 
174         if (StartsObjCMethodExpr) {
175           CurrentToken->Type = TT_ObjCMethodExpr;
176           if (Contexts.back().FirstObjCSelectorName) {
177             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
178                 Contexts.back().LongestObjCSelectorName;
179           }
180         }
181 
182         if (Left->Type == TT_AttributeParen)
183           CurrentToken->Type = TT_AttributeParen;
184 
185         if (!HasMultipleLines)
186           Left->PackingKind = PPK_Inconclusive;
187         else if (HasMultipleParametersOnALine)
188           Left->PackingKind = PPK_BinPacked;
189         else
190           Left->PackingKind = PPK_OnePerLine;
191 
192         next();
193         return true;
194       }
195       if (CurrentToken->isOneOf(tok::r_square, tok::r_brace))
196         return false;
197       else if (CurrentToken->is(tok::l_brace))
198         Left->Type = TT_Unknown; // Not TT_ObjCBlockLParen
199       if (CurrentToken->is(tok::comma) && CurrentToken->Next &&
200           !CurrentToken->Next->HasUnescapedNewline &&
201           !CurrentToken->Next->isTrailingComment())
202         HasMultipleParametersOnALine = true;
203       if (CurrentToken->isOneOf(tok::kw_const, tok::kw_auto) ||
204           CurrentToken->isSimpleTypeSpecifier())
205         Contexts.back().IsExpression = false;
206       FormatToken *Tok = CurrentToken;
207       if (!consumeToken())
208         return false;
209       updateParameterCount(Left, Tok);
210       if (CurrentToken && CurrentToken->HasUnescapedNewline)
211         HasMultipleLines = true;
212     }
213     return false;
214   }
215 
216   bool parseSquare() {
217     if (!CurrentToken)
218       return false;
219 
220     // A '[' could be an index subscript (after an identifier or after
221     // ')' or ']'), it could be the start of an Objective-C method
222     // expression, or it could the the start of an Objective-C array literal.
223     FormatToken *Left = CurrentToken->Previous;
224     FormatToken *Parent = Left->getPreviousNonComment();
225     bool StartsObjCMethodExpr =
226         Contexts.back().CanBeExpression && Left->Type != TT_LambdaLSquare &&
227         CurrentToken->isNot(tok::l_brace) &&
228         (!Parent || Parent->isOneOf(tok::colon, tok::l_square, tok::l_paren,
229                                     tok::kw_return, tok::kw_throw) ||
230          Parent->isUnaryOperator() || Parent->Type == TT_ObjCForIn ||
231          Parent->Type == TT_CastRParen ||
232          getBinOpPrecedence(Parent->Tok.getKind(), true, true) > prec::Unknown);
233     ScopedContextCreator ContextCreator(*this, tok::l_square, 10);
234     Contexts.back().IsExpression = true;
235     bool ColonFound = false;
236 
237     if (StartsObjCMethodExpr) {
238       Contexts.back().ColonIsObjCMethodExpr = true;
239       Left->Type = TT_ObjCMethodExpr;
240     } else if (Parent && Parent->is(tok::at)) {
241       Left->Type = TT_ArrayInitializerLSquare;
242     } else if (Left->Type == TT_Unknown) {
243       Left->Type = TT_ArraySubscriptLSquare;
244     }
245 
246     while (CurrentToken) {
247       if (CurrentToken->is(tok::r_square)) {
248         if (CurrentToken->Next && CurrentToken->Next->is(tok::l_paren) &&
249             Left->Type == TT_ObjCMethodExpr) {
250           // An ObjC method call is rarely followed by an open parenthesis.
251           // FIXME: Do we incorrectly label ":" with this?
252           StartsObjCMethodExpr = false;
253           Left->Type = TT_Unknown;
254         }
255         if (StartsObjCMethodExpr && CurrentToken->Previous != Left) {
256           CurrentToken->Type = TT_ObjCMethodExpr;
257           // determineStarAmpUsage() thinks that '*' '[' is allocating an
258           // array of pointers, but if '[' starts a selector then '*' is a
259           // binary operator.
260           if (Parent && Parent->Type == TT_PointerOrReference)
261             Parent->Type = TT_BinaryOperator;
262         }
263         Left->MatchingParen = CurrentToken;
264         CurrentToken->MatchingParen = Left;
265         if (Contexts.back().FirstObjCSelectorName) {
266           Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
267               Contexts.back().LongestObjCSelectorName;
268           if (Left->BlockParameterCount > 1)
269             Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName = 0;
270         }
271         next();
272         return true;
273       }
274       if (CurrentToken->isOneOf(tok::r_paren, tok::r_brace))
275         return false;
276       if (CurrentToken->is(tok::colon))
277         ColonFound = true;
278       if (CurrentToken->is(tok::comma) &&
279           Style.Language != FormatStyle::LK_Proto &&
280           (Left->Type == TT_ArraySubscriptLSquare ||
281            (Left->Type == TT_ObjCMethodExpr && !ColonFound)))
282         Left->Type = TT_ArrayInitializerLSquare;
283       FormatToken* Tok = CurrentToken;
284       if (!consumeToken())
285         return false;
286       updateParameterCount(Left, Tok);
287     }
288     return false;
289   }
290 
291   bool parseBrace() {
292     if (CurrentToken) {
293       FormatToken *Left = CurrentToken->Previous;
294 
295       if (Contexts.back().CaretFound)
296         Left->Type = TT_ObjCBlockLBrace;
297       Contexts.back().CaretFound = false;
298 
299       ScopedContextCreator ContextCreator(*this, tok::l_brace, 1);
300       Contexts.back().ColonIsDictLiteral = true;
301       if (Left->BlockKind == BK_BracedInit)
302         Contexts.back().IsExpression = true;
303 
304       while (CurrentToken) {
305         if (CurrentToken->is(tok::r_brace)) {
306           Left->MatchingParen = CurrentToken;
307           CurrentToken->MatchingParen = Left;
308           next();
309           return true;
310         }
311         if (CurrentToken->isOneOf(tok::r_paren, tok::r_square))
312           return false;
313         updateParameterCount(Left, CurrentToken);
314         if (CurrentToken->is(tok::colon)) {
315           if (CurrentToken->getPreviousNonComment()->is(tok::identifier))
316             CurrentToken->getPreviousNonComment()->Type = TT_SelectorName;
317           Left->Type = TT_DictLiteral;
318         }
319         if (!consumeToken())
320           return false;
321       }
322     }
323     return true;
324   }
325 
326   void updateParameterCount(FormatToken *Left, FormatToken *Current) {
327     if (Current->Type == TT_LambdaLSquare ||
328         (Current->is(tok::caret) && Current->Type == TT_UnaryOperator) ||
329         (Style.Language == FormatStyle::LK_JavaScript &&
330          Current->TokenText == "function")) {
331       ++Left->BlockParameterCount;
332     }
333     if (Current->is(tok::comma)) {
334       ++Left->ParameterCount;
335       if (!Left->Role)
336         Left->Role.reset(new CommaSeparatedList(Style));
337       Left->Role->CommaFound(Current);
338     } else if (Left->ParameterCount == 0 && Current->isNot(tok::comment)) {
339       Left->ParameterCount = 1;
340     }
341   }
342 
343   bool parseConditional() {
344     while (CurrentToken) {
345       if (CurrentToken->is(tok::colon)) {
346         CurrentToken->Type = TT_ConditionalExpr;
347         next();
348         return true;
349       }
350       if (!consumeToken())
351         return false;
352     }
353     return false;
354   }
355 
356   bool parseTemplateDeclaration() {
357     if (CurrentToken && CurrentToken->is(tok::less)) {
358       CurrentToken->Type = TT_TemplateOpener;
359       next();
360       if (!parseAngle())
361         return false;
362       if (CurrentToken)
363         CurrentToken->Previous->ClosesTemplateDeclaration = true;
364       return true;
365     }
366     return false;
367   }
368 
369   bool consumeToken() {
370     FormatToken *Tok = CurrentToken;
371     next();
372     switch (Tok->Tok.getKind()) {
373     case tok::plus:
374     case tok::minus:
375       if (!Tok->Previous && Line.MustBeDeclaration)
376         Tok->Type = TT_ObjCMethodSpecifier;
377       break;
378     case tok::colon:
379       if (!Tok->Previous)
380         return false;
381       // Colons from ?: are handled in parseConditional().
382       if (Tok->Previous->is(tok::r_paren) && Contexts.size() == 1 &&
383           Line.First->isNot(tok::kw_case)) {
384         Tok->Type = TT_CtorInitializerColon;
385       } else if (Contexts.back().ColonIsDictLiteral) {
386         Tok->Type = TT_DictLiteral;
387       } else if (Contexts.back().ColonIsObjCMethodExpr ||
388                  Line.First->Type == TT_ObjCMethodSpecifier) {
389         Tok->Type = TT_ObjCMethodExpr;
390         Tok->Previous->Type = TT_SelectorName;
391         if (Tok->Previous->ColumnWidth >
392             Contexts.back().LongestObjCSelectorName) {
393           Contexts.back().LongestObjCSelectorName = Tok->Previous->ColumnWidth;
394         }
395         if (!Contexts.back().FirstObjCSelectorName)
396           Contexts.back().FirstObjCSelectorName = Tok->Previous;
397       } else if (Contexts.back().ColonIsForRangeExpr) {
398         Tok->Type = TT_RangeBasedForLoopColon;
399       } else if (CurrentToken && CurrentToken->is(tok::numeric_constant)) {
400         Tok->Type = TT_BitFieldColon;
401       } else if (Contexts.size() == 1 &&
402                  !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) {
403         Tok->Type = TT_InheritanceColon;
404       } else if (Contexts.back().ContextKind == tok::l_paren) {
405         Tok->Type = TT_InlineASMColon;
406       }
407       break;
408     case tok::kw_if:
409     case tok::kw_while:
410       if (CurrentToken && CurrentToken->is(tok::l_paren)) {
411         next();
412         if (!parseParens(/*LookForDecls=*/true))
413           return false;
414       }
415       break;
416     case tok::kw_for:
417       Contexts.back().ColonIsForRangeExpr = true;
418       next();
419       if (!parseParens())
420         return false;
421       break;
422     case tok::l_paren:
423       if (!parseParens())
424         return false;
425       if (Line.MustBeDeclaration && Contexts.size() == 1 &&
426           !Contexts.back().IsExpression &&
427           Line.First->Type != TT_ObjCProperty &&
428           (!Tok->Previous || Tok->Previous->isNot(tok::kw_decltype)))
429         Line.MightBeFunctionDecl = true;
430       break;
431     case tok::l_square:
432       if (!parseSquare())
433         return false;
434       break;
435     case tok::l_brace:
436       if (!parseBrace())
437         return false;
438       break;
439     case tok::less:
440       if (Tok->Previous && !Tok->Previous->Tok.isLiteral() && parseAngle())
441         Tok->Type = TT_TemplateOpener;
442       else {
443         Tok->Type = TT_BinaryOperator;
444         CurrentToken = Tok;
445         next();
446       }
447       break;
448     case tok::r_paren:
449     case tok::r_square:
450       return false;
451     case tok::r_brace:
452       // Lines can start with '}'.
453       if (Tok->Previous)
454         return false;
455       break;
456     case tok::greater:
457       Tok->Type = TT_BinaryOperator;
458       break;
459     case tok::kw_operator:
460       while (CurrentToken &&
461              !CurrentToken->isOneOf(tok::l_paren, tok::semi, tok::r_paren)) {
462         if (CurrentToken->isOneOf(tok::star, tok::amp))
463           CurrentToken->Type = TT_PointerOrReference;
464         consumeToken();
465         if (CurrentToken && CurrentToken->Previous->Type == TT_BinaryOperator)
466           CurrentToken->Previous->Type = TT_OverloadedOperator;
467       }
468       if (CurrentToken) {
469         CurrentToken->Type = TT_OverloadedOperatorLParen;
470         if (CurrentToken->Previous->Type == TT_BinaryOperator)
471           CurrentToken->Previous->Type = TT_OverloadedOperator;
472       }
473       break;
474     case tok::question:
475       parseConditional();
476       break;
477     case tok::kw_template:
478       parseTemplateDeclaration();
479       break;
480     case tok::identifier:
481       if (Line.First->is(tok::kw_for) &&
482           Tok->Tok.getIdentifierInfo() == &Ident_in)
483         Tok->Type = TT_ObjCForIn;
484       break;
485     case tok::comma:
486       if (Contexts.back().FirstStartOfName)
487         Contexts.back().FirstStartOfName->PartOfMultiVariableDeclStmt = true;
488       if (Contexts.back().InCtorInitializer)
489         Tok->Type = TT_CtorInitializerComma;
490       if (Contexts.back().IsForEachMacro)
491         Contexts.back().IsExpression = true;
492       break;
493     default:
494       break;
495     }
496     return true;
497   }
498 
499   void parseIncludeDirective() {
500     if (CurrentToken && CurrentToken->is(tok::less)) {
501       next();
502       while (CurrentToken) {
503         if (CurrentToken->isNot(tok::comment) || CurrentToken->Next)
504           CurrentToken->Type = TT_ImplicitStringLiteral;
505         next();
506       }
507     } else {
508       while (CurrentToken) {
509         if (CurrentToken->is(tok::string_literal))
510           // Mark these string literals as "implicit" literals, too, so that
511           // they are not split or line-wrapped.
512           CurrentToken->Type = TT_ImplicitStringLiteral;
513         next();
514       }
515     }
516   }
517 
518   void parseWarningOrError() {
519     next();
520     // We still want to format the whitespace left of the first token of the
521     // warning or error.
522     next();
523     while (CurrentToken) {
524       CurrentToken->Type = TT_ImplicitStringLiteral;
525       next();
526     }
527   }
528 
529   void parsePragma() {
530     next(); // Consume "pragma".
531     if (CurrentToken && CurrentToken->TokenText == "mark") {
532       next(); // Consume "mark".
533       next(); // Consume first token (so we fix leading whitespace).
534       while (CurrentToken) {
535         CurrentToken->Type = TT_ImplicitStringLiteral;
536         next();
537       }
538     }
539   }
540 
541   void parsePreprocessorDirective() {
542     next();
543     if (!CurrentToken)
544       return;
545     if (CurrentToken->Tok.is(tok::numeric_constant)) {
546       CurrentToken->SpacesRequiredBefore = 1;
547       return;
548     }
549     // Hashes in the middle of a line can lead to any strange token
550     // sequence.
551     if (!CurrentToken->Tok.getIdentifierInfo())
552       return;
553     switch (CurrentToken->Tok.getIdentifierInfo()->getPPKeywordID()) {
554     case tok::pp_include:
555     case tok::pp_import:
556       next();
557       parseIncludeDirective();
558       break;
559     case tok::pp_error:
560     case tok::pp_warning:
561       parseWarningOrError();
562       break;
563     case tok::pp_pragma:
564       parsePragma();
565       break;
566     case tok::pp_if:
567     case tok::pp_elif:
568       Contexts.back().IsExpression = true;
569       parseLine();
570       break;
571     default:
572       break;
573     }
574     while (CurrentToken)
575       next();
576   }
577 
578 public:
579   LineType parseLine() {
580     if (CurrentToken->is(tok::hash)) {
581       parsePreprocessorDirective();
582       return LT_PreprocessorDirective;
583     }
584 
585     // Directly allow to 'import <string-literal>' to support protocol buffer
586     // definitions (code.google.com/p/protobuf) or missing "#" (either way we
587     // should not break the line).
588     IdentifierInfo *Info = CurrentToken->Tok.getIdentifierInfo();
589     if (Info && Info->getPPKeywordID() == tok::pp_import &&
590         CurrentToken->Next && CurrentToken->Next->is(tok::string_literal)) {
591       next();
592       parseIncludeDirective();
593       return LT_Other;
594     }
595 
596     // If this line starts and ends in '<' and '>', respectively, it is likely
597     // part of "#define <a/b.h>".
598     if (CurrentToken->is(tok::less) && Line.Last->is(tok::greater)) {
599       parseIncludeDirective();
600       return LT_Other;
601     }
602 
603     while (CurrentToken) {
604       if (CurrentToken->is(tok::kw_virtual))
605         KeywordVirtualFound = true;
606       if (!consumeToken())
607         return LT_Invalid;
608     }
609     if (KeywordVirtualFound)
610       return LT_VirtualFunctionDecl;
611 
612     if (Line.First->Type == TT_ObjCMethodSpecifier) {
613       if (Contexts.back().FirstObjCSelectorName)
614         Contexts.back().FirstObjCSelectorName->LongestObjCSelectorName =
615             Contexts.back().LongestObjCSelectorName;
616       return LT_ObjCMethodDecl;
617     }
618 
619     return LT_Other;
620   }
621 
622 private:
623   void resetTokenMetadata(FormatToken *Token) {
624     if (!Token)
625       return;
626 
627     // Reset token type in case we have already looked at it and then
628     // recovered from an error (e.g. failure to find the matching >).
629     if (CurrentToken->Type != TT_LambdaLSquare &&
630         CurrentToken->Type != TT_FunctionLBrace &&
631         CurrentToken->Type != TT_ImplicitStringLiteral &&
632         CurrentToken->Type != TT_RegexLiteral &&
633         CurrentToken->Type != TT_TrailingReturnArrow)
634       CurrentToken->Type = TT_Unknown;
635     CurrentToken->Role.reset();
636     CurrentToken->FakeLParens.clear();
637     CurrentToken->FakeRParens = 0;
638   }
639 
640   void next() {
641     if (CurrentToken) {
642       determineTokenType(*CurrentToken);
643       CurrentToken->BindingStrength = Contexts.back().BindingStrength;
644       CurrentToken->NestingLevel = Contexts.size() - 1;
645       CurrentToken = CurrentToken->Next;
646     }
647 
648     resetTokenMetadata(CurrentToken);
649   }
650 
651   /// \brief A struct to hold information valid in a specific context, e.g.
652   /// a pair of parenthesis.
653   struct Context {
654     Context(tok::TokenKind ContextKind, unsigned BindingStrength,
655             bool IsExpression)
656         : ContextKind(ContextKind), BindingStrength(BindingStrength),
657           LongestObjCSelectorName(0), ColonIsForRangeExpr(false),
658           ColonIsDictLiteral(false), ColonIsObjCMethodExpr(false),
659           FirstObjCSelectorName(nullptr), FirstStartOfName(nullptr),
660           IsExpression(IsExpression), CanBeExpression(true),
661           InTemplateArgument(false), InCtorInitializer(false),
662           CaretFound(false), IsForEachMacro(false) {}
663 
664     tok::TokenKind ContextKind;
665     unsigned BindingStrength;
666     unsigned LongestObjCSelectorName;
667     bool ColonIsForRangeExpr;
668     bool ColonIsDictLiteral;
669     bool ColonIsObjCMethodExpr;
670     FormatToken *FirstObjCSelectorName;
671     FormatToken *FirstStartOfName;
672     bool IsExpression;
673     bool CanBeExpression;
674     bool InTemplateArgument;
675     bool InCtorInitializer;
676     bool CaretFound;
677     bool IsForEachMacro;
678   };
679 
680   /// \brief Puts a new \c Context onto the stack \c Contexts for the lifetime
681   /// of each instance.
682   struct ScopedContextCreator {
683     AnnotatingParser &P;
684 
685     ScopedContextCreator(AnnotatingParser &P, tok::TokenKind ContextKind,
686                          unsigned Increase)
687         : P(P) {
688       P.Contexts.push_back(Context(ContextKind,
689                                    P.Contexts.back().BindingStrength + Increase,
690                                    P.Contexts.back().IsExpression));
691     }
692 
693     ~ScopedContextCreator() { P.Contexts.pop_back(); }
694   };
695 
696   void determineTokenType(FormatToken &Current) {
697     if (Current.getPrecedence() == prec::Assignment &&
698         !Line.First->isOneOf(tok::kw_template, tok::kw_using) &&
699         (!Current.Previous || Current.Previous->isNot(tok::kw_operator))) {
700       Contexts.back().IsExpression = true;
701       for (FormatToken *Previous = Current.Previous;
702            Previous && !Previous->isOneOf(tok::comma, tok::semi);
703            Previous = Previous->Previous) {
704         if (Previous->isOneOf(tok::r_square, tok::r_paren)) {
705           Previous = Previous->MatchingParen;
706           if (!Previous)
707             break;
708         }
709         if ((Previous->Type == TT_BinaryOperator ||
710              Previous->Type == TT_UnaryOperator) &&
711             Previous->isOneOf(tok::star, tok::amp)) {
712           Previous->Type = TT_PointerOrReference;
713         }
714       }
715     } else if (Current.isOneOf(tok::kw_return, tok::kw_throw)) {
716       Contexts.back().IsExpression = true;
717     } else if (Current.is(tok::l_paren) && !Line.MustBeDeclaration &&
718                !Line.InPPDirective &&
719                (!Current.Previous ||
720                 Current.Previous->isNot(tok::kw_decltype))) {
721       bool ParametersOfFunctionType =
722           Current.Previous && Current.Previous->is(tok::r_paren) &&
723           Current.Previous->MatchingParen &&
724           Current.Previous->MatchingParen->Type == TT_FunctionTypeLParen;
725       bool IsForOrCatch = Current.Previous &&
726                           Current.Previous->isOneOf(tok::kw_for, tok::kw_catch);
727       Contexts.back().IsExpression = !ParametersOfFunctionType && !IsForOrCatch;
728     } else if (Current.isOneOf(tok::r_paren, tok::greater, tok::comma)) {
729       for (FormatToken *Previous = Current.Previous;
730            Previous && Previous->isOneOf(tok::star, tok::amp);
731            Previous = Previous->Previous)
732         Previous->Type = TT_PointerOrReference;
733     } else if (Current.Previous &&
734                Current.Previous->Type == TT_CtorInitializerColon) {
735       Contexts.back().IsExpression = true;
736       Contexts.back().InCtorInitializer = true;
737     } else if (Current.is(tok::kw_new)) {
738       Contexts.back().CanBeExpression = false;
739     } else if (Current.is(tok::semi) || Current.is(tok::exclaim)) {
740       // This should be the condition or increment in a for-loop.
741       Contexts.back().IsExpression = true;
742     }
743 
744     if (Current.Type == TT_Unknown) {
745       // Line.MightBeFunctionDecl can only be true after the parentheses of a
746       // function declaration have been found. In this case, 'Current' is a
747       // trailing token of this declaration and thus cannot be a name.
748       if (isStartOfName(Current) && !Line.MightBeFunctionDecl) {
749         Contexts.back().FirstStartOfName = &Current;
750         Current.Type = TT_StartOfName;
751       } else if (Current.is(tok::kw_auto)) {
752         AutoFound = true;
753       } else if (Current.is(tok::arrow) && AutoFound &&
754                  Line.MustBeDeclaration) {
755         Current.Type = TT_TrailingReturnArrow;
756       } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
757         Current.Type =
758             determineStarAmpUsage(Current, Contexts.back().CanBeExpression &&
759                                                Contexts.back().IsExpression,
760                                   Contexts.back().InTemplateArgument);
761       } else if (Current.isOneOf(tok::minus, tok::plus, tok::caret)) {
762         Current.Type = determinePlusMinusCaretUsage(Current);
763         if (Current.Type == TT_UnaryOperator && Current.is(tok::caret))
764           Contexts.back().CaretFound = true;
765       } else if (Current.isOneOf(tok::minusminus, tok::plusplus)) {
766         Current.Type = determineIncrementUsage(Current);
767       } else if (Current.isOneOf(tok::exclaim, tok::tilde)) {
768         Current.Type = TT_UnaryOperator;
769       } else if (Current.is(tok::question)) {
770         Current.Type = TT_ConditionalExpr;
771       } else if (Current.isBinaryOperator() &&
772                  (!Current.Previous ||
773                   Current.Previous->isNot(tok::l_square))) {
774         Current.Type = TT_BinaryOperator;
775       } else if (Current.is(tok::comment)) {
776         if (Current.TokenText.startswith("//"))
777           Current.Type = TT_LineComment;
778         else
779           Current.Type = TT_BlockComment;
780       } else if (Current.is(tok::r_paren)) {
781         if (rParenEndsCast(Current))
782           Current.Type = TT_CastRParen;
783       } else if (Current.is(tok::at) && Current.Next) {
784         switch (Current.Next->Tok.getObjCKeywordID()) {
785         case tok::objc_interface:
786         case tok::objc_implementation:
787         case tok::objc_protocol:
788           Current.Type = TT_ObjCDecl;
789           break;
790         case tok::objc_property:
791           Current.Type = TT_ObjCProperty;
792           break;
793         default:
794           break;
795         }
796       } else if (Current.is(tok::period)) {
797         FormatToken *PreviousNoComment = Current.getPreviousNonComment();
798         if (PreviousNoComment &&
799             PreviousNoComment->isOneOf(tok::comma, tok::l_brace))
800           Current.Type = TT_DesignatedInitializerPeriod;
801       } else if (Current.isOneOf(tok::identifier, tok::kw_const) &&
802                  Current.Previous && Current.Previous->isNot(tok::equal) &&
803                  Line.MightBeFunctionDecl && Contexts.size() == 1) {
804         // Line.MightBeFunctionDecl can only be true after the parentheses of a
805         // function declaration have been found.
806         Current.Type = TT_TrailingAnnotation;
807       }
808     }
809   }
810 
811   /// \brief Take a guess at whether \p Tok starts a name of a function or
812   /// variable declaration.
813   ///
814   /// This is a heuristic based on whether \p Tok is an identifier following
815   /// something that is likely a type.
816   bool isStartOfName(const FormatToken &Tok) {
817     if (Tok.isNot(tok::identifier) || !Tok.Previous)
818       return false;
819 
820     // Skip "const" as it does not have an influence on whether this is a name.
821     FormatToken *PreviousNotConst = Tok.Previous;
822     while (PreviousNotConst && PreviousNotConst->is(tok::kw_const))
823       PreviousNotConst = PreviousNotConst->Previous;
824 
825     if (!PreviousNotConst)
826       return false;
827 
828     bool IsPPKeyword = PreviousNotConst->is(tok::identifier) &&
829                        PreviousNotConst->Previous &&
830                        PreviousNotConst->Previous->is(tok::hash);
831 
832     if (PreviousNotConst->Type == TT_TemplateCloser)
833       return PreviousNotConst && PreviousNotConst->MatchingParen &&
834              PreviousNotConst->MatchingParen->Previous &&
835              PreviousNotConst->MatchingParen->Previous->isNot(tok::kw_template);
836 
837     if (PreviousNotConst->is(tok::r_paren) && PreviousNotConst->MatchingParen &&
838         PreviousNotConst->MatchingParen->Previous &&
839         PreviousNotConst->MatchingParen->Previous->is(tok::kw_decltype))
840       return true;
841 
842     return (!IsPPKeyword && PreviousNotConst->is(tok::identifier)) ||
843            PreviousNotConst->Type == TT_PointerOrReference ||
844            PreviousNotConst->isSimpleTypeSpecifier();
845   }
846 
847   /// \brief Determine whether ')' is ending a cast.
848   bool rParenEndsCast(const FormatToken &Tok) {
849     FormatToken *LeftOfParens = nullptr;
850     if (Tok.MatchingParen)
851       LeftOfParens = Tok.MatchingParen->getPreviousNonComment();
852     if (LeftOfParens && LeftOfParens->is(tok::r_paren))
853       return false;
854     if (LeftOfParens && LeftOfParens->is(tok::r_square) &&
855         LeftOfParens->MatchingParen &&
856         LeftOfParens->MatchingParen->Type == TT_LambdaLSquare)
857       return false;
858     bool IsCast = false;
859     bool ParensAreEmpty = Tok.Previous == Tok.MatchingParen;
860     bool ParensAreType = !Tok.Previous ||
861                          Tok.Previous->Type == TT_PointerOrReference ||
862                          Tok.Previous->Type == TT_TemplateCloser ||
863                          Tok.Previous->isSimpleTypeSpecifier();
864     bool ParensCouldEndDecl =
865         Tok.Next && Tok.Next->isOneOf(tok::equal, tok::semi, tok::l_brace);
866     bool IsSizeOfOrAlignOf =
867         LeftOfParens && LeftOfParens->isOneOf(tok::kw_sizeof, tok::kw_alignof);
868     if (ParensAreType && !ParensCouldEndDecl && !IsSizeOfOrAlignOf &&
869         ((Contexts.size() > 1 && Contexts[Contexts.size() - 2].IsExpression) ||
870          (Tok.Next && Tok.Next->isBinaryOperator())))
871       IsCast = true;
872     else if (Tok.Next && Tok.Next->isNot(tok::string_literal) &&
873              (Tok.Next->Tok.isLiteral() ||
874               Tok.Next->isOneOf(tok::kw_sizeof, tok::kw_alignof)))
875       IsCast = true;
876     // If there is an identifier after the (), it is likely a cast, unless
877     // there is also an identifier before the ().
878     else if (LeftOfParens &&
879              (LeftOfParens->Tok.getIdentifierInfo() == nullptr ||
880               LeftOfParens->is(tok::kw_return)) &&
881              LeftOfParens->Type != TT_OverloadedOperator &&
882              LeftOfParens->isNot(tok::at) &&
883              LeftOfParens->Type != TT_TemplateCloser && Tok.Next) {
884       if (Tok.Next->isOneOf(tok::identifier, tok::numeric_constant)) {
885         IsCast = true;
886       } else {
887         // Use heuristics to recognize c style casting.
888         FormatToken *Prev = Tok.Previous;
889         if (Prev && Prev->isOneOf(tok::amp, tok::star))
890           Prev = Prev->Previous;
891 
892         if (Prev && Tok.Next && Tok.Next->Next) {
893           bool NextIsUnary = Tok.Next->isUnaryOperator() ||
894                              Tok.Next->isOneOf(tok::amp, tok::star);
895           IsCast = NextIsUnary && Tok.Next->Next->isOneOf(
896                                       tok::identifier, tok::numeric_constant);
897         }
898 
899         for (; Prev != Tok.MatchingParen; Prev = Prev->Previous) {
900           if (!Prev || !Prev->isOneOf(tok::kw_const, tok::identifier)) {
901             IsCast = false;
902             break;
903           }
904         }
905       }
906     }
907     return IsCast && !ParensAreEmpty;
908   }
909 
910   /// \brief Return the type of the given token assuming it is * or &.
911   TokenType determineStarAmpUsage(const FormatToken &Tok, bool IsExpression,
912                                   bool InTemplateArgument) {
913     const FormatToken *PrevToken = Tok.getPreviousNonComment();
914     if (!PrevToken)
915       return TT_UnaryOperator;
916 
917     const FormatToken *NextToken = Tok.getNextNonComment();
918     if (!NextToken || NextToken->is(tok::l_brace))
919       return TT_Unknown;
920 
921     if (PrevToken->is(tok::coloncolon) ||
922         (PrevToken->is(tok::l_paren) && !IsExpression))
923       return TT_PointerOrReference;
924 
925     if (PrevToken->isOneOf(tok::l_paren, tok::l_square, tok::l_brace,
926                            tok::comma, tok::semi, tok::kw_return, tok::colon,
927                            tok::equal, tok::kw_delete, tok::kw_sizeof) ||
928         PrevToken->Type == TT_BinaryOperator ||
929         PrevToken->Type == TT_ConditionalExpr ||
930         PrevToken->Type == TT_UnaryOperator || PrevToken->Type == TT_CastRParen)
931       return TT_UnaryOperator;
932 
933     if (NextToken->is(tok::l_square) && NextToken->Type != TT_LambdaLSquare)
934       return TT_PointerOrReference;
935     if (NextToken->isOneOf(tok::kw_operator, tok::comma))
936       return TT_PointerOrReference;
937 
938     if (PrevToken->is(tok::r_paren) && PrevToken->MatchingParen &&
939         PrevToken->MatchingParen->Previous &&
940         PrevToken->MatchingParen->Previous->isOneOf(tok::kw_typeof,
941                                                     tok::kw_decltype))
942       return TT_PointerOrReference;
943 
944     if (PrevToken->Tok.isLiteral() ||
945         PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::kw_true,
946                            tok::kw_false) ||
947         NextToken->Tok.isLiteral() ||
948         NextToken->isOneOf(tok::kw_true, tok::kw_false) ||
949         NextToken->isUnaryOperator() ||
950         // If we know we're in a template argument, there are no named
951         // declarations. Thus, having an identifier on the right-hand side
952         // indicates a binary operator.
953         (InTemplateArgument && NextToken->Tok.isAnyIdentifier()))
954       return TT_BinaryOperator;
955 
956     // This catches some cases where evaluation order is used as control flow:
957     //   aaa && aaa->f();
958     const FormatToken *NextNextToken = NextToken->getNextNonComment();
959     if (NextNextToken && NextNextToken->is(tok::arrow))
960       return TT_BinaryOperator;
961 
962     // It is very unlikely that we are going to find a pointer or reference type
963     // definition on the RHS of an assignment.
964     if (IsExpression)
965       return TT_BinaryOperator;
966 
967     return TT_PointerOrReference;
968   }
969 
970   TokenType determinePlusMinusCaretUsage(const FormatToken &Tok) {
971     const FormatToken *PrevToken = Tok.getPreviousNonComment();
972     if (!PrevToken || PrevToken->Type == TT_CastRParen)
973       return TT_UnaryOperator;
974 
975     // Use heuristics to recognize unary operators.
976     if (PrevToken->isOneOf(tok::equal, tok::l_paren, tok::comma, tok::l_square,
977                            tok::question, tok::colon, tok::kw_return,
978                            tok::kw_case, tok::at, tok::l_brace))
979       return TT_UnaryOperator;
980 
981     // There can't be two consecutive binary operators.
982     if (PrevToken->Type == TT_BinaryOperator)
983       return TT_UnaryOperator;
984 
985     // Fall back to marking the token as binary operator.
986     return TT_BinaryOperator;
987   }
988 
989   /// \brief Determine whether ++/-- are pre- or post-increments/-decrements.
990   TokenType determineIncrementUsage(const FormatToken &Tok) {
991     const FormatToken *PrevToken = Tok.getPreviousNonComment();
992     if (!PrevToken || PrevToken->Type == TT_CastRParen)
993       return TT_UnaryOperator;
994     if (PrevToken->isOneOf(tok::r_paren, tok::r_square, tok::identifier))
995       return TT_TrailingUnaryOperator;
996 
997     return TT_UnaryOperator;
998   }
999 
1000   SmallVector<Context, 8> Contexts;
1001 
1002   const FormatStyle &Style;
1003   AnnotatedLine &Line;
1004   FormatToken *CurrentToken;
1005   bool KeywordVirtualFound;
1006   bool AutoFound;
1007   IdentifierInfo &Ident_in;
1008 };
1009 
1010 static int PrecedenceUnaryOperator = prec::PointerToMember + 1;
1011 static int PrecedenceArrowAndPeriod = prec::PointerToMember + 2;
1012 
1013 /// \brief Parses binary expressions by inserting fake parenthesis based on
1014 /// operator precedence.
1015 class ExpressionParser {
1016 public:
1017   ExpressionParser(AnnotatedLine &Line) : Current(Line.First) {
1018     // Skip leading "}", e.g. in "} else if (...) {".
1019     if (Current->is(tok::r_brace))
1020       next();
1021   }
1022 
1023   /// \brief Parse expressions with the given operatore precedence.
1024   void parse(int Precedence = 0) {
1025     // Skip 'return' and ObjC selector colons as they are not part of a binary
1026     // expression.
1027     while (Current &&
1028            (Current->is(tok::kw_return) ||
1029             (Current->is(tok::colon) && (Current->Type == TT_ObjCMethodExpr ||
1030                                          Current->Type == TT_DictLiteral))))
1031       next();
1032 
1033     if (!Current || Precedence > PrecedenceArrowAndPeriod)
1034       return;
1035 
1036     // Conditional expressions need to be parsed separately for proper nesting.
1037     if (Precedence == prec::Conditional) {
1038       parseConditionalExpr();
1039       return;
1040     }
1041 
1042     // Parse unary operators, which all have a higher precedence than binary
1043     // operators.
1044     if (Precedence == PrecedenceUnaryOperator) {
1045       parseUnaryOperator();
1046       return;
1047     }
1048 
1049     FormatToken *Start = Current;
1050     FormatToken *LatestOperator = nullptr;
1051     unsigned OperatorIndex = 0;
1052 
1053     while (Current) {
1054       // Consume operators with higher precedence.
1055       parse(Precedence + 1);
1056 
1057       int CurrentPrecedence = getCurrentPrecedence();
1058 
1059       if (Current && Current->Type == TT_SelectorName &&
1060           Precedence == CurrentPrecedence) {
1061         if (LatestOperator)
1062           addFakeParenthesis(Start, prec::Level(Precedence));
1063         Start = Current;
1064       }
1065 
1066       // At the end of the line or when an operator with higher precedence is
1067       // found, insert fake parenthesis and return.
1068       if (!Current || Current->closesScope() ||
1069           (CurrentPrecedence != -1 && CurrentPrecedence < Precedence)) {
1070         if (LatestOperator) {
1071           LatestOperator->LastOperator = true;
1072           if (Precedence == PrecedenceArrowAndPeriod) {
1073             // Call expressions don't have a binary operator precedence.
1074             addFakeParenthesis(Start, prec::Unknown);
1075           } else {
1076             addFakeParenthesis(Start, prec::Level(Precedence));
1077           }
1078         }
1079         return;
1080       }
1081 
1082       // Consume scopes: (), [], <> and {}
1083       if (Current->opensScope()) {
1084         while (Current && !Current->closesScope()) {
1085           next();
1086           parse();
1087         }
1088         next();
1089       } else {
1090         // Operator found.
1091         if (CurrentPrecedence == Precedence) {
1092           LatestOperator = Current;
1093           Current->OperatorIndex = OperatorIndex;
1094           ++OperatorIndex;
1095         }
1096 
1097         next();
1098       }
1099     }
1100   }
1101 
1102 private:
1103   /// \brief Gets the precedence (+1) of the given token for binary operators
1104   /// and other tokens that we treat like binary operators.
1105   int getCurrentPrecedence() {
1106     if (Current) {
1107       if (Current->Type == TT_ConditionalExpr)
1108         return prec::Conditional;
1109       else if (Current->is(tok::semi) || Current->Type == TT_InlineASMColon ||
1110                Current->Type == TT_SelectorName)
1111         return 0;
1112       else if (Current->Type == TT_RangeBasedForLoopColon)
1113         return prec::Comma;
1114       else if (Current->Type == TT_BinaryOperator || Current->is(tok::comma))
1115         return Current->getPrecedence();
1116       else if (Current->isOneOf(tok::period, tok::arrow))
1117         return PrecedenceArrowAndPeriod;
1118     }
1119     return -1;
1120   }
1121 
1122   void addFakeParenthesis(FormatToken *Start, prec::Level Precedence) {
1123     Start->FakeLParens.push_back(Precedence);
1124     if (Precedence > prec::Unknown)
1125       Start->StartsBinaryExpression = true;
1126     if (Current) {
1127       ++Current->Previous->FakeRParens;
1128       if (Precedence > prec::Unknown)
1129         Current->Previous->EndsBinaryExpression = true;
1130     }
1131   }
1132 
1133   /// \brief Parse unary operator expressions and surround them with fake
1134   /// parentheses if appropriate.
1135   void parseUnaryOperator() {
1136     if (!Current || Current->Type != TT_UnaryOperator) {
1137       parse(PrecedenceArrowAndPeriod);
1138       return;
1139     }
1140 
1141     FormatToken *Start = Current;
1142     next();
1143     parseUnaryOperator();
1144 
1145     // The actual precedence doesn't matter.
1146     addFakeParenthesis(Start, prec::Unknown);
1147   }
1148 
1149   void parseConditionalExpr() {
1150     FormatToken *Start = Current;
1151     parse(prec::LogicalOr);
1152     if (!Current || !Current->is(tok::question))
1153       return;
1154     next();
1155     parseConditionalExpr();
1156     if (!Current || Current->Type != TT_ConditionalExpr)
1157       return;
1158     next();
1159     parseConditionalExpr();
1160     addFakeParenthesis(Start, prec::Conditional);
1161   }
1162 
1163   void next() {
1164     if (Current)
1165       Current = Current->Next;
1166     while (Current && Current->isTrailingComment())
1167       Current = Current->Next;
1168   }
1169 
1170   FormatToken *Current;
1171 };
1172 
1173 } // end anonymous namespace
1174 
1175 void
1176 TokenAnnotator::setCommentLineLevels(SmallVectorImpl<AnnotatedLine *> &Lines) {
1177   const AnnotatedLine *NextNonCommentLine = nullptr;
1178   for (SmallVectorImpl<AnnotatedLine *>::reverse_iterator I = Lines.rbegin(),
1179                                                           E = Lines.rend();
1180        I != E; ++I) {
1181     if (NextNonCommentLine && (*I)->First->is(tok::comment) &&
1182         (*I)->First->Next == nullptr)
1183       (*I)->Level = NextNonCommentLine->Level;
1184     else
1185       NextNonCommentLine = (*I)->First->isNot(tok::r_brace) ? (*I) : nullptr;
1186 
1187     setCommentLineLevels((*I)->Children);
1188   }
1189 }
1190 
1191 void TokenAnnotator::annotate(AnnotatedLine &Line) {
1192   for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
1193                                                   E = Line.Children.end();
1194        I != E; ++I) {
1195     annotate(**I);
1196   }
1197   AnnotatingParser Parser(Style, Line, Ident_in);
1198   Line.Type = Parser.parseLine();
1199   if (Line.Type == LT_Invalid)
1200     return;
1201 
1202   ExpressionParser ExprParser(Line);
1203   ExprParser.parse();
1204 
1205   if (Line.First->Type == TT_ObjCMethodSpecifier)
1206     Line.Type = LT_ObjCMethodDecl;
1207   else if (Line.First->Type == TT_ObjCDecl)
1208     Line.Type = LT_ObjCDecl;
1209   else if (Line.First->Type == TT_ObjCProperty)
1210     Line.Type = LT_ObjCProperty;
1211 
1212   Line.First->SpacesRequiredBefore = 1;
1213   Line.First->CanBreakBefore = Line.First->MustBreakBefore;
1214 }
1215 
1216 // This function heuristically determines whether 'Current' starts the name of a
1217 // function declaration.
1218 static bool isFunctionDeclarationName(const FormatToken &Current) {
1219   if (Current.Type != TT_StartOfName ||
1220       Current.NestingLevel != 0 ||
1221       Current.Previous->Type == TT_StartOfName)
1222     return false;
1223   const FormatToken *Next = Current.Next;
1224   for (; Next; Next = Next->Next) {
1225     if (Next->Type == TT_TemplateOpener) {
1226       Next = Next->MatchingParen;
1227     } else if (Next->is(tok::coloncolon)) {
1228       Next = Next->Next;
1229       if (!Next || !Next->is(tok::identifier))
1230         return false;
1231     } else if (Next->is(tok::l_paren)) {
1232       break;
1233     } else {
1234       return false;
1235     }
1236   }
1237   if (!Next)
1238     return false;
1239   assert(Next->is(tok::l_paren));
1240   if (Next->Next == Next->MatchingParen)
1241     return true;
1242   for (const FormatToken *Tok = Next->Next; Tok != Next->MatchingParen;
1243        Tok = Tok->Next) {
1244     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
1245         Tok->Type == TT_PointerOrReference || Tok->Type == TT_StartOfName)
1246       return true;
1247     if (Tok->isOneOf(tok::l_brace, tok::string_literal) || Tok->Tok.isLiteral())
1248       return false;
1249   }
1250   return false;
1251 }
1252 
1253 void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
1254   for (SmallVectorImpl<AnnotatedLine *>::iterator I = Line.Children.begin(),
1255                                                   E = Line.Children.end();
1256        I != E; ++I) {
1257     calculateFormattingInformation(**I);
1258   }
1259 
1260   Line.First->TotalLength =
1261       Line.First->IsMultiline ? Style.ColumnLimit : Line.First->ColumnWidth;
1262   if (!Line.First->Next)
1263     return;
1264   FormatToken *Current = Line.First->Next;
1265   bool InFunctionDecl = Line.MightBeFunctionDecl;
1266   while (Current) {
1267     if (isFunctionDeclarationName(*Current))
1268       Current->Type = TT_FunctionDeclarationName;
1269     if (Current->Type == TT_LineComment) {
1270       if (Current->Previous->BlockKind == BK_BracedInit &&
1271           Current->Previous->opensScope())
1272         Current->SpacesRequiredBefore = Style.Cpp11BracedListStyle ? 0 : 1;
1273       else
1274         Current->SpacesRequiredBefore = Style.SpacesBeforeTrailingComments;
1275 
1276       // If we find a trailing comment, iterate backwards to determine whether
1277       // it seems to relate to a specific parameter. If so, break before that
1278       // parameter to avoid changing the comment's meaning. E.g. don't move 'b'
1279       // to the previous line in:
1280       //   SomeFunction(a,
1281       //                b, // comment
1282       //                c);
1283       if (!Current->HasUnescapedNewline) {
1284         for (FormatToken *Parameter = Current->Previous; Parameter;
1285              Parameter = Parameter->Previous) {
1286           if (Parameter->isOneOf(tok::comment, tok::r_brace))
1287             break;
1288           if (Parameter->Previous && Parameter->Previous->is(tok::comma)) {
1289             if (Parameter->Previous->Type != TT_CtorInitializerComma &&
1290                 Parameter->HasUnescapedNewline)
1291               Parameter->MustBreakBefore = true;
1292             break;
1293           }
1294         }
1295       }
1296     } else if (Current->SpacesRequiredBefore == 0 &&
1297                spaceRequiredBefore(Line, *Current)) {
1298       Current->SpacesRequiredBefore = 1;
1299     }
1300 
1301     Current->MustBreakBefore =
1302         Current->MustBreakBefore || mustBreakBefore(Line, *Current);
1303 
1304     if (Style.AlwaysBreakAfterDefinitionReturnType &&
1305         InFunctionDecl && Current->Type == TT_FunctionDeclarationName &&
1306         Line.Last->is(tok::l_brace))  // Only for definitions.
1307       Current->MustBreakBefore = true;
1308 
1309     Current->CanBreakBefore =
1310         Current->MustBreakBefore || canBreakBefore(Line, *Current);
1311     unsigned ChildSize = 0;
1312     if (Current->Previous->Children.size() == 1) {
1313       FormatToken &LastOfChild = *Current->Previous->Children[0]->Last;
1314       ChildSize = LastOfChild.isTrailingComment() ? Style.ColumnLimit
1315                                                   : LastOfChild.TotalLength + 1;
1316     }
1317     if (Current->MustBreakBefore || Current->Previous->Children.size() > 1 ||
1318         Current->IsMultiline)
1319       Current->TotalLength = Current->Previous->TotalLength + Style.ColumnLimit;
1320     else
1321       Current->TotalLength = Current->Previous->TotalLength +
1322                              Current->ColumnWidth + ChildSize +
1323                              Current->SpacesRequiredBefore;
1324 
1325     if (Current->Type == TT_CtorInitializerColon)
1326       InFunctionDecl = false;
1327 
1328     // FIXME: Only calculate this if CanBreakBefore is true once static
1329     // initializers etc. are sorted out.
1330     // FIXME: Move magic numbers to a better place.
1331     Current->SplitPenalty = 20 * Current->BindingStrength +
1332                             splitPenalty(Line, *Current, InFunctionDecl);
1333 
1334     Current = Current->Next;
1335   }
1336 
1337   calculateUnbreakableTailLengths(Line);
1338   for (Current = Line.First; Current != nullptr; Current = Current->Next) {
1339     if (Current->Role)
1340       Current->Role->precomputeFormattingInfos(Current);
1341   }
1342 
1343   DEBUG({ printDebugInfo(Line); });
1344 }
1345 
1346 void TokenAnnotator::calculateUnbreakableTailLengths(AnnotatedLine &Line) {
1347   unsigned UnbreakableTailLength = 0;
1348   FormatToken *Current = Line.Last;
1349   while (Current) {
1350     Current->UnbreakableTailLength = UnbreakableTailLength;
1351     if (Current->CanBreakBefore ||
1352         Current->isOneOf(tok::comment, tok::string_literal)) {
1353       UnbreakableTailLength = 0;
1354     } else {
1355       UnbreakableTailLength +=
1356           Current->ColumnWidth + Current->SpacesRequiredBefore;
1357     }
1358     Current = Current->Previous;
1359   }
1360 }
1361 
1362 unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
1363                                       const FormatToken &Tok,
1364                                       bool InFunctionDecl) {
1365   const FormatToken &Left = *Tok.Previous;
1366   const FormatToken &Right = Tok;
1367 
1368   if (Left.is(tok::semi))
1369     return 0;
1370   if (Left.is(tok::comma) || (Right.is(tok::identifier) && Right.Next &&
1371                               Right.Next->Type == TT_DictLiteral))
1372     return 1;
1373   if (Right.is(tok::l_square)) {
1374     if (Style.Language == FormatStyle::LK_Proto)
1375       return 1;
1376     if (Right.Type != TT_ObjCMethodExpr && Right.Type != TT_LambdaLSquare)
1377       return 500;
1378   }
1379   if (Right.Type == TT_StartOfName ||
1380       Right.Type == TT_FunctionDeclarationName || Right.is(tok::kw_operator)) {
1381     if (Line.First->is(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
1382       return 3;
1383     if (Left.Type == TT_StartOfName)
1384       return 20;
1385     if (InFunctionDecl && Right.NestingLevel == 0)
1386       return Style.PenaltyReturnTypeOnItsOwnLine;
1387     return 200;
1388   }
1389   if (Left.is(tok::equal) && Right.is(tok::l_brace))
1390     return 150;
1391   if (Left.Type == TT_CastRParen)
1392     return 100;
1393   if (Left.is(tok::coloncolon) ||
1394       (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
1395     return 500;
1396   if (Left.isOneOf(tok::kw_class, tok::kw_struct))
1397     return 5000;
1398 
1399   if (Left.Type == TT_RangeBasedForLoopColon ||
1400       Left.Type == TT_InheritanceColon)
1401     return 2;
1402 
1403   if (Right.isMemberAccess()) {
1404     if (Left.is(tok::r_paren) && Left.MatchingParen &&
1405         Left.MatchingParen->ParameterCount > 0)
1406       return 20; // Should be smaller than breaking at a nested comma.
1407     return 150;
1408   }
1409 
1410   if (Right.Type == TT_TrailingAnnotation &&
1411       (!Right.Next || Right.Next->isNot(tok::l_paren))) {
1412     // Generally, breaking before a trailing annotation is bad unless it is
1413     // function-like. It seems to be especially preferable to keep standard
1414     // annotations (i.e. "const", "final" and "override") on the same line.
1415     // Use a slightly higher penalty after ")" so that annotations like
1416     // "const override" are kept together.
1417     bool is_short_annotation = Right.TokenText.size() < 10;
1418     return (Left.is(tok::r_paren) ? 100 : 120) + (is_short_annotation ? 50 : 0);
1419   }
1420 
1421   // In for-loops, prefer breaking at ',' and ';'.
1422   if (Line.First->is(tok::kw_for) && Left.is(tok::equal))
1423     return 4;
1424 
1425   // In Objective-C method expressions, prefer breaking before "param:" over
1426   // breaking after it.
1427   if (Right.Type == TT_SelectorName)
1428     return 0;
1429   if (Left.is(tok::colon) && Left.Type == TT_ObjCMethodExpr)
1430     return Line.MightBeFunctionDecl ? 50 : 500;
1431 
1432   if (Left.is(tok::l_paren) && InFunctionDecl)
1433     return 100;
1434   if (Left.is(tok::equal) && InFunctionDecl)
1435     return 110;
1436   if (Right.is(tok::r_brace))
1437     return 1;
1438   if (Left.opensScope())
1439     return Left.ParameterCount > 1 ? Style.PenaltyBreakBeforeFirstCallParameter
1440                                    : 19;
1441 
1442   if (Right.is(tok::lessless)) {
1443     if (Left.is(tok::string_literal)) {
1444       StringRef Content = Left.TokenText;
1445       if (Content.startswith("\""))
1446         Content = Content.drop_front(1);
1447       if (Content.endswith("\""))
1448         Content = Content.drop_back(1);
1449       Content = Content.trim();
1450       if (Content.size() > 1 &&
1451           (Content.back() == ':' || Content.back() == '='))
1452         return 25;
1453     }
1454     return 1; // Breaking at a << is really cheap.
1455   }
1456   if (Left.Type == TT_ConditionalExpr)
1457     return prec::Conditional;
1458   prec::Level Level = Left.getPrecedence();
1459 
1460   if (Level != prec::Unknown)
1461     return Level;
1462 
1463   return 3;
1464 }
1465 
1466 bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
1467                                           const FormatToken &Left,
1468                                           const FormatToken &Right) {
1469   if (Style.Language == FormatStyle::LK_Proto) {
1470     if (Right.is(tok::period) &&
1471         (Left.TokenText == "optional" || Left.TokenText == "required" ||
1472          Left.TokenText == "repeated"))
1473       return true;
1474     if (Right.is(tok::l_paren) &&
1475         (Left.TokenText == "returns" || Left.TokenText == "option"))
1476       return true;
1477   } else if (Style.Language == FormatStyle::LK_JavaScript) {
1478     if (Left.TokenText == "var")
1479       return true;
1480   }
1481   if (Left.is(tok::kw_return) && Right.isNot(tok::semi))
1482     return true;
1483   if (Style.ObjCSpaceAfterProperty && Line.Type == LT_ObjCProperty &&
1484       Left.Tok.getObjCKeywordID() == tok::objc_property)
1485     return true;
1486   if (Right.is(tok::hashhash))
1487     return Left.is(tok::hash);
1488   if (Left.isOneOf(tok::hashhash, tok::hash))
1489     return Right.is(tok::hash);
1490   if (Left.is(tok::l_paren) && Right.is(tok::r_paren))
1491     return Style.SpaceInEmptyParentheses;
1492   if (Left.is(tok::l_paren) || Right.is(tok::r_paren))
1493     return (Right.Type == TT_CastRParen ||
1494             (Left.MatchingParen && Left.MatchingParen->Type == TT_CastRParen))
1495                ? Style.SpacesInCStyleCastParentheses
1496                : Style.SpacesInParentheses;
1497   if (Style.SpacesInAngles &&
1498       ((Left.Type == TT_TemplateOpener) != (Right.Type == TT_TemplateCloser)))
1499     return true;
1500   if (Right.isOneOf(tok::semi, tok::comma))
1501     return false;
1502   if (Right.is(tok::less) &&
1503       (Left.isOneOf(tok::kw_template, tok::r_paren) ||
1504        (Line.Type == LT_ObjCDecl && Style.ObjCSpaceBeforeProtocolList)))
1505     return true;
1506   if (Left.is(tok::arrow) || Right.is(tok::arrow))
1507     return false;
1508   if (Left.isOneOf(tok::exclaim, tok::tilde))
1509     return false;
1510   if (Left.is(tok::at) &&
1511       Right.isOneOf(tok::identifier, tok::string_literal, tok::char_constant,
1512                     tok::numeric_constant, tok::l_paren, tok::l_brace,
1513                     tok::kw_true, tok::kw_false))
1514     return false;
1515   if (Left.is(tok::coloncolon))
1516     return false;
1517   if (Right.is(tok::coloncolon) && Left.isNot(tok::l_brace))
1518     return (Left.is(tok::less) && Style.Standard == FormatStyle::LS_Cpp03) ||
1519            !Left.isOneOf(tok::identifier, tok::greater, tok::l_paren,
1520                          tok::r_paren, tok::less);
1521   if (Left.is(tok::less) || Right.isOneOf(tok::greater, tok::less))
1522     return false;
1523   if (Right.is(tok::ellipsis))
1524     return Left.Tok.isLiteral();
1525   if (Left.is(tok::l_square) && Right.is(tok::amp))
1526     return false;
1527   if (Right.Type == TT_PointerOrReference)
1528     return Left.Tok.isLiteral() ||
1529            ((Left.Type != TT_PointerOrReference) && Left.isNot(tok::l_paren) &&
1530             Style.PointerAlignment != FormatStyle::PAS_Left);
1531   if (Right.Type == TT_FunctionTypeLParen && Left.isNot(tok::l_paren) &&
1532       (Left.Type != TT_PointerOrReference ||
1533        Style.PointerAlignment != FormatStyle::PAS_Right))
1534     return true;
1535   if (Left.Type == TT_PointerOrReference)
1536     return Right.Tok.isLiteral() || Right.Type == TT_BlockComment ||
1537            ((Right.Type != TT_PointerOrReference) &&
1538             Right.isNot(tok::l_paren) &&
1539             Style.PointerAlignment != FormatStyle::PAS_Right && Left.Previous &&
1540             !Left.Previous->isOneOf(tok::l_paren, tok::coloncolon));
1541   if (Right.is(tok::star) && Left.is(tok::l_paren))
1542     return false;
1543   if (Left.is(tok::l_square))
1544     return Left.Type == TT_ArrayInitializerLSquare &&
1545            Style.SpacesInContainerLiterals && Right.isNot(tok::r_square);
1546   if (Right.is(tok::r_square))
1547     return Right.MatchingParen && Style.SpacesInContainerLiterals &&
1548            Right.MatchingParen->Type == TT_ArrayInitializerLSquare;
1549   if (Right.is(tok::l_square) && Right.Type != TT_ObjCMethodExpr &&
1550       Right.Type != TT_LambdaLSquare && Left.isNot(tok::numeric_constant) &&
1551       Left.Type != TT_DictLiteral)
1552     return false;
1553   if (Left.is(tok::colon))
1554     return Left.Type != TT_ObjCMethodExpr;
1555   if (Left.Type == TT_BlockComment)
1556     return !Left.TokenText.endswith("=*/");
1557   if (Right.is(tok::l_paren)) {
1558     if (Left.is(tok::r_paren) && Left.Type == TT_AttributeParen)
1559       return true;
1560     return Line.Type == LT_ObjCDecl ||
1561            Left.isOneOf(tok::kw_new, tok::kw_delete, tok::semi) ||
1562            (Style.SpaceBeforeParens != FormatStyle::SBPO_Never &&
1563             (Left.isOneOf(tok::kw_if, tok::kw_for, tok::kw_while,
1564                           tok::kw_switch, tok::kw_catch, tok::kw_case) ||
1565              Left.IsForEachMacro)) ||
1566            (Style.SpaceBeforeParens == FormatStyle::SBPO_Always &&
1567             (Left.is(tok::identifier) || Left.isFunctionLikeKeyword()) &&
1568             Line.Type != LT_PreprocessorDirective);
1569   }
1570   if (Left.is(tok::at) && Right.Tok.getObjCKeywordID() != tok::objc_not_keyword)
1571     return false;
1572   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
1573     return !Left.Children.empty(); // No spaces in "{}".
1574   if ((Left.is(tok::l_brace) && Left.BlockKind != BK_Block) ||
1575       (Right.is(tok::r_brace) && Right.MatchingParen &&
1576        Right.MatchingParen->BlockKind != BK_Block))
1577     return !Style.Cpp11BracedListStyle;
1578   if (Right.Type == TT_UnaryOperator)
1579     return !Left.isOneOf(tok::l_paren, tok::l_square, tok::at) &&
1580            (Left.isNot(tok::colon) || Left.Type != TT_ObjCMethodExpr);
1581   if ((Left.isOneOf(tok::identifier, tok::greater, tok::r_square,
1582                     tok::r_paren) ||
1583        Left.isSimpleTypeSpecifier()) &&
1584       Right.is(tok::l_brace) && Right.getNextNonComment() &&
1585       Right.BlockKind != BK_Block)
1586     return false;
1587   if (Left.is(tok::period) || Right.is(tok::period))
1588     return false;
1589   if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
1590     return false;
1591   return true;
1592 }
1593 
1594 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
1595                                          const FormatToken &Tok) {
1596   if (Tok.Tok.getIdentifierInfo() && Tok.Previous->Tok.getIdentifierInfo())
1597     return true; // Never ever merge two identifiers.
1598   if (Tok.Previous->Type == TT_ImplicitStringLiteral)
1599     return Tok.WhitespaceRange.getBegin() != Tok.WhitespaceRange.getEnd();
1600   if (Line.Type == LT_ObjCMethodDecl) {
1601     if (Tok.Previous->Type == TT_ObjCMethodSpecifier)
1602       return true;
1603     if (Tok.Previous->is(tok::r_paren) && Tok.is(tok::identifier))
1604       // Don't space between ')' and <id>
1605       return false;
1606   }
1607   if (Line.Type == LT_ObjCProperty &&
1608       (Tok.is(tok::equal) || Tok.Previous->is(tok::equal)))
1609     return false;
1610 
1611   if (Tok.Type == TT_TrailingReturnArrow ||
1612       Tok.Previous->Type == TT_TrailingReturnArrow)
1613     return true;
1614   if (Tok.Previous->is(tok::comma))
1615     return true;
1616   if (Tok.is(tok::comma))
1617     return false;
1618   if (Tok.Type == TT_CtorInitializerColon || Tok.Type == TT_ObjCBlockLParen)
1619     return true;
1620   if (Tok.Previous->Tok.is(tok::kw_operator))
1621     return Tok.is(tok::coloncolon);
1622   if (Tok.Type == TT_OverloadedOperatorLParen)
1623     return false;
1624   if (Tok.is(tok::colon))
1625     return !Line.First->isOneOf(tok::kw_case, tok::kw_default) &&
1626            Tok.getNextNonComment() && Tok.Type != TT_ObjCMethodExpr &&
1627            !Tok.Previous->is(tok::question) &&
1628            (Tok.Type != TT_DictLiteral || Style.SpacesInContainerLiterals);
1629   if (Tok.Previous->Type == TT_UnaryOperator ||
1630       Tok.Previous->Type == TT_CastRParen)
1631     return Tok.Type == TT_BinaryOperator;
1632   if (Tok.Previous->is(tok::greater) && Tok.is(tok::greater)) {
1633     return Tok.Type == TT_TemplateCloser &&
1634            Tok.Previous->Type == TT_TemplateCloser &&
1635            (Style.Standard != FormatStyle::LS_Cpp11 || Style.SpacesInAngles);
1636   }
1637   if (Tok.isOneOf(tok::arrowstar, tok::periodstar) ||
1638       Tok.Previous->isOneOf(tok::arrowstar, tok::periodstar))
1639     return false;
1640   if (!Style.SpaceBeforeAssignmentOperators &&
1641       Tok.getPrecedence() == prec::Assignment)
1642     return false;
1643   if ((Tok.Type == TT_BinaryOperator && !Tok.Previous->is(tok::l_paren)) ||
1644       Tok.Previous->Type == TT_BinaryOperator ||
1645       Tok.Previous->Type == TT_ConditionalExpr)
1646     return true;
1647   if (Tok.Previous->Type == TT_TemplateCloser && Tok.is(tok::l_paren))
1648     return Style.SpaceBeforeParens == FormatStyle::SBPO_Always;
1649   if (Tok.is(tok::less) && Tok.Previous->isNot(tok::l_paren) &&
1650       Line.First->is(tok::hash))
1651     return true;
1652   if (Tok.Type == TT_TrailingUnaryOperator)
1653     return false;
1654   if (Tok.Previous->Type == TT_RegexLiteral)
1655     return false;
1656   return spaceRequiredBetween(Line, *Tok.Previous, Tok);
1657 }
1658 
1659 // Returns 'true' if 'Tok' is a brace we'd want to break before in Allman style.
1660 static bool isAllmanBrace(const FormatToken &Tok) {
1661   return Tok.is(tok::l_brace) && Tok.BlockKind == BK_Block &&
1662          Tok.Type != TT_ObjCBlockLBrace && Tok.Type != TT_DictLiteral;
1663 }
1664 
1665 bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
1666                                      const FormatToken &Right) {
1667   const FormatToken &Left = *Right.Previous;
1668   if (Right.NewlinesBefore > 1)
1669     return true;
1670   if (Right.is(tok::comment)) {
1671     return Right.Previous->BlockKind != BK_BracedInit &&
1672            Right.Previous->Type != TT_CtorInitializerColon &&
1673            (Right.NewlinesBefore > 0 && Right.HasUnescapedNewline);
1674   } else if (Right.Previous->isTrailingComment() ||
1675              (Right.isStringLiteral() && Right.Previous->isStringLiteral())) {
1676     return true;
1677   } else if (Right.Previous->IsUnterminatedLiteral) {
1678     return true;
1679   } else if (Right.is(tok::lessless) && Right.Next &&
1680              Right.Previous->is(tok::string_literal) &&
1681              Right.Next->is(tok::string_literal)) {
1682     return true;
1683   } else if (Right.Previous->ClosesTemplateDeclaration &&
1684              Right.Previous->MatchingParen &&
1685              Right.Previous->MatchingParen->NestingLevel == 0 &&
1686              Style.AlwaysBreakTemplateDeclarations) {
1687     return true;
1688   } else if ((Right.Type == TT_CtorInitializerComma ||
1689               Right.Type == TT_CtorInitializerColon) &&
1690              Style.BreakConstructorInitializersBeforeComma &&
1691              !Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
1692     return true;
1693   } else if (Right.is(tok::string_literal) &&
1694              Right.TokenText.startswith("R\"")) {
1695     // Raw string literals are special wrt. line breaks. The author has made a
1696     // deliberate choice and might have aligned the contents of the string
1697     // literal accordingly. Thus, we try keep existing line breaks.
1698     return Right.NewlinesBefore > 0;
1699   } else if (Right.Previous->is(tok::l_brace) && Right.NestingLevel == 1 &&
1700              Style.Language == FormatStyle::LK_Proto) {
1701     // Don't enums onto single lines in protocol buffers.
1702     return true;
1703   } else if (isAllmanBrace(Left) || isAllmanBrace(Right)) {
1704     return Style.BreakBeforeBraces == FormatStyle::BS_Allman ||
1705            Style.BreakBeforeBraces == FormatStyle::BS_GNU;
1706   } else if (Style.Language == FormatStyle::LK_Proto &&
1707              Left.isNot(tok::l_brace) && Right.Type == TT_SelectorName) {
1708     return true;
1709   }
1710 
1711   // If the last token before a '}' is a comma or a comment, the intention is to
1712   // insert a line break after it in order to make shuffling around entries
1713   // easier.
1714   const FormatToken *BeforeClosingBrace = nullptr;
1715   if (Left.is(tok::l_brace) && Left.MatchingParen)
1716     BeforeClosingBrace = Left.MatchingParen->Previous;
1717   else if (Right.is(tok::r_brace))
1718     BeforeClosingBrace = Right.Previous;
1719   if (BeforeClosingBrace &&
1720       BeforeClosingBrace->isOneOf(tok::comma, tok::comment))
1721     return true;
1722 
1723   if (Style.Language == FormatStyle::LK_JavaScript) {
1724     // FIXME: This might apply to other languages and token kinds.
1725     if (Right.is(tok::char_constant) && Left.is(tok::plus) && Left.Previous &&
1726         Left.Previous->is(tok::char_constant))
1727       return true;
1728   }
1729 
1730   return false;
1731 }
1732 
1733 bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
1734                                     const FormatToken &Right) {
1735   const FormatToken &Left = *Right.Previous;
1736   if (Left.is(tok::at))
1737     return false;
1738   if (Left.Tok.getObjCKeywordID() == tok::objc_interface)
1739     return false;
1740   if (Right.Type == TT_StartOfName ||
1741       Right.Type == TT_FunctionDeclarationName || Right.is(tok::kw_operator))
1742     return true;
1743   if (Right.isTrailingComment())
1744     // We rely on MustBreakBefore being set correctly here as we should not
1745     // change the "binding" behavior of a comment.
1746     // The first comment in a braced lists is always interpreted as belonging to
1747     // the first list element. Otherwise, it should be placed outside of the
1748     // list.
1749     return Left.BlockKind == BK_BracedInit;
1750   if (Left.is(tok::question) && Right.is(tok::colon))
1751     return false;
1752   if (Right.Type == TT_ConditionalExpr || Right.is(tok::question))
1753     return Style.BreakBeforeTernaryOperators;
1754   if (Left.Type == TT_ConditionalExpr || Left.is(tok::question))
1755     return !Style.BreakBeforeTernaryOperators;
1756   if (Right.Type == TT_InheritanceColon)
1757     return true;
1758   if (Right.is(tok::colon) && (Right.Type != TT_CtorInitializerColon &&
1759                                Right.Type != TT_InlineASMColon))
1760     return false;
1761   if (Left.is(tok::colon) &&
1762       (Left.Type == TT_DictLiteral || Left.Type == TT_ObjCMethodExpr))
1763     return true;
1764   if (Right.Type == TT_SelectorName)
1765     return true;
1766   if (Left.is(tok::r_paren) && Line.Type == LT_ObjCProperty)
1767     return true;
1768   if (Left.ClosesTemplateDeclaration)
1769     return true;
1770   if (Right.Type == TT_RangeBasedForLoopColon ||
1771       Right.Type == TT_OverloadedOperatorLParen ||
1772       Right.Type == TT_OverloadedOperator)
1773     return false;
1774   if (Left.Type == TT_RangeBasedForLoopColon)
1775     return true;
1776   if (Right.Type == TT_RangeBasedForLoopColon)
1777     return false;
1778   if (Left.Type == TT_PointerOrReference || Left.Type == TT_TemplateCloser ||
1779       Left.Type == TT_UnaryOperator || Left.is(tok::kw_operator))
1780     return false;
1781   if (Left.is(tok::equal) && Line.Type == LT_VirtualFunctionDecl)
1782     return false;
1783   if (Left.is(tok::l_paren) && Left.Type == TT_AttributeParen)
1784     return false;
1785   if (Left.is(tok::l_paren) && Left.Previous &&
1786       (Left.Previous->Type == TT_BinaryOperator ||
1787        Left.Previous->Type == TT_CastRParen || Left.Previous->is(tok::kw_if)))
1788     return false;
1789   if (Right.Type == TT_ImplicitStringLiteral)
1790     return false;
1791 
1792   if (Right.is(tok::r_paren) || Right.Type == TT_TemplateCloser)
1793     return false;
1794 
1795   // We only break before r_brace if there was a corresponding break before
1796   // the l_brace, which is tracked by BreakBeforeClosingBrace.
1797   if (Right.is(tok::r_brace))
1798     return Right.MatchingParen && Right.MatchingParen->BlockKind == BK_Block;
1799 
1800   // Allow breaking after a trailing annotation, e.g. after a method
1801   // declaration.
1802   if (Left.Type == TT_TrailingAnnotation)
1803     return !Right.isOneOf(tok::l_brace, tok::semi, tok::equal, tok::l_paren,
1804                           tok::less, tok::coloncolon);
1805 
1806   if (Right.is(tok::kw___attribute))
1807     return true;
1808 
1809   if (Left.is(tok::identifier) && Right.is(tok::string_literal))
1810     return true;
1811 
1812   if (Right.is(tok::identifier) && Right.Next &&
1813       Right.Next->Type == TT_DictLiteral)
1814     return true;
1815 
1816   if (Left.Type == TT_CtorInitializerComma &&
1817       Style.BreakConstructorInitializersBeforeComma)
1818     return false;
1819   if (Right.Type == TT_CtorInitializerComma &&
1820       Style.BreakConstructorInitializersBeforeComma)
1821     return true;
1822   if (Left.is(tok::greater) && Right.is(tok::greater) &&
1823       Left.Type != TT_TemplateCloser)
1824     return false;
1825   if (Right.Type == TT_BinaryOperator && Style.BreakBeforeBinaryOperators)
1826     return true;
1827   if (Left.Type == TT_ArrayInitializerLSquare)
1828     return true;
1829   if (Right.is(tok::kw_typename) && Left.isNot(tok::kw_const))
1830     return true;
1831   return (Left.isBinaryOperator() &&
1832           !Left.isOneOf(tok::arrowstar, tok::lessless) &&
1833           !Style.BreakBeforeBinaryOperators) ||
1834          Left.isOneOf(tok::comma, tok::coloncolon, tok::semi, tok::l_brace,
1835                       tok::kw_class, tok::kw_struct) ||
1836          Right.isMemberAccess() ||
1837          Right.isOneOf(tok::lessless, tok::colon, tok::l_square, tok::at) ||
1838          (Left.is(tok::r_paren) &&
1839           Right.isOneOf(tok::identifier, tok::kw_const)) ||
1840          (Left.is(tok::l_paren) && !Right.is(tok::r_paren));
1841 }
1842 
1843 void TokenAnnotator::printDebugInfo(const AnnotatedLine &Line) {
1844   llvm::errs() << "AnnotatedTokens:\n";
1845   const FormatToken *Tok = Line.First;
1846   while (Tok) {
1847     llvm::errs() << " M=" << Tok->MustBreakBefore
1848                  << " C=" << Tok->CanBreakBefore << " T=" << Tok->Type
1849                  << " S=" << Tok->SpacesRequiredBefore
1850                  << " B=" << Tok->BlockParameterCount
1851                  << " P=" << Tok->SplitPenalty << " Name=" << Tok->Tok.getName()
1852                  << " L=" << Tok->TotalLength << " PPK=" << Tok->PackingKind
1853                  << " FakeLParens=";
1854     for (unsigned i = 0, e = Tok->FakeLParens.size(); i != e; ++i)
1855       llvm::errs() << Tok->FakeLParens[i] << "/";
1856     llvm::errs() << " FakeRParens=" << Tok->FakeRParens << "\n";
1857     if (!Tok->Next)
1858       assert(Tok == Line.Last);
1859     Tok = Tok->Next;
1860   }
1861   llvm::errs() << "----\n";
1862 }
1863 
1864 } // namespace format
1865 } // namespace clang
1866